Research at Massachusetts General Hospital looks increasingly like a long-term cure for type 1 diabetes, with a newly released study on Thursday showing patients have normal blood sugar levels eight years after a clinical trial.

In research published Thursday in journal npj Vaccines, patients who had been treated with the bacillus Calmette-Guerin (BCG) vaccine -- an inexpensive, generic vaccine used around the world to prevent tuberculosis -- had normal blood sugar levels eight years after the trial ended.

While it took three years for patients to see results from the vaccine, two doses of the drug spaced four weeks apart were still having a lasting impact eight years later.

"It's kind of big news," said Dr. Denise Faustman, director of the Massachusetts General Hospital immunobiology laboratory and principal investigator of the trial. "It's the first trial showing (long-term reversal of diabetes), and more trials are on the way. But scientifically it's pretty cool."

The recently published study also details how the vaccine genetically alters the body's white blood cells so they process glucose, making up for the pancreas' inability to produce insulin to do the same. In type 1 diabetes -- referred to in the past as juvenile diabetes -- the immune system damages the pancreas and blocks the cells from producing insulin.

"It's not only the discovery that something cheap in new cohorts brings down blood sugar, but why. We've discovered new pathways for lowering blood sugar," Faustman said. "It's an important discovery for the basic science of diabetes care. And by the way, we have a cheap BCG vaccine that seems to be doing it."

Faustman has been working for over a decade on trials of the treatment, first in mice and then in humans. In addition to follow-ups with patients from the phase 1 clinical trial, a phase 2 clinical trial, which has been funded largely by support from the Iacocca Family Foundation, is ongoing. Faustman's lab is still seeking the final $2 million of the $25 million cost.

The goal of the latest clinical trial is to replicate results from the first phase, as well as to analyze the dosing necessary to make the vaccine work quickly. The study isn't accepting more patients, but Faustman encouraged patients to sign up when the trial is hopefully expanded.

News of the dramatic results has been trickling out as Faustman progresses work with the vaccine. Last year, Faustman discussed the research on the mechanism of the drug at the Scientific Sessions of the American Diabetes Association and in an interview with the Boston Business Journal. She said she waited until the eight-year clinical results were ready to publish the findings on how the drug works, in order to give more credence to the vaccine's success.

Used in China, Africa and South America to vaccinate against TB, the BCG vaccine has been used 4 billion times over the last 100 years. Last year alone, 100 million doses of the vaccine were given to newborns. Because TB isn't common in the U.S., children here do not receive the vaccine.

Faustman's trial is one of several happening nationally on BCG. There is ongoing research into the drug's effect on multiple sclerosis in Italy, and on food allergies in Australia.

The microorganism originates from the dirt. Faustman said the rise of autoimmune disorders, and the increase of food allergies and gluten intolerance, is tied to the fact that humans no longer interact with dirt in the way they once did.

Faustman has her sights set on more than just completing the phase 2 clinical trial. She hopes to also conduct a trial on the vaccine in children with type 1 diabetes, and to possibly make the drug available for right-to-try trials. There could also be future studies on whether the drug can work in type 2 diabetes.

"It's a significant advance since the discovery of insulin, and it needs to be duplicated and replicated and expanded," Faustman said.